Room temperature organic magnets derived from sp3 functionalized graphene
添加于 2017/3/8 9:32:24 140次阅读 | 0次推荐 | 5个评论
Materials based on metallic elements that have d orbitals and exhibit room temperature magnetism have been known for centuries and applied in a huge range of technologies. Development of room temperature carbon magnets containing exclusively sp orbitals is viewed as great challenge in chemistry, physics, spintronics and materials science. Here we describe a series of room temperature organic magnets prepared by a simple and controllable route based on the substitution of fluorine atoms in fluorographene with hydroxyl groups. Depending on the chemical composition (an F/OH ratio) and sp3 coverage, these new graphene derivatives show room temperature antiferromagnetic ordering, which has never been observed for any sp-based materials. Such 2D magnets undergo a transition to a ferromagnetic state at low temperatures, showing an extraordinarily high magnetic moment. The developed theoretical model addresses the origin of the room temperature magnetism in terms of sp2-conjugated diradical motifs embedded in an sp3 matrix and superexchange interactions via –OH functionalization.
Jiří Tuček, Kateřina Holá, Athanasios B. Bourlinos, Piotr Błoński, Aristides Bakandritsos, Juri Ugolotti, Matúš Dubecky, František Karlicky, Václav Ranc, Klára Čépe, Michal Otyepka & Radek Zbořil
Published online: 20 February 2017 第8卷 第期 Article number: 14525页
工程材料 » 无机非金属材料 » 无机非金属类光电信息与功能材料
A dream of many generations of researchers has been fulfilled by a discovery made by scientists at the Regional Centre of Advanced Technologies and Materials (RCPTM) at the Palacky University in Olomouc. By using graphene, an ultrathin form of carbon, these scientists prepared the first non-metallic magnet that retains its magnetic properties up to room temperature. In doing so, they disproved the old belief that all materials with room temperature magnetism are based on metals or their compounds. Chemically modified magnetic graphene has a vast range of potential applications, particularly in the fields of biomedicine and electronics. The work of the Czech scientists has recently been published in Nature Communications.